Field of the Invention
The present invention relates to a wearable device, and more particularly, to a wearable device and controlling method thereof. Although the present invention is suitable for a wide scope of applications, it is particularly suitable for enabling user authentication in a manner of obtaining user's biometric image using a flexible surface light source and a photo panel.
Discussion of the Related Art
Generally, the object of the vein authentication technology is to obtain vein blood vessel information differing for each person. Such a technology can identify a person in a manner of applying infrared ray of a specific wavelength, photographing with an image sensor, and then extracting a blood vessel pattern represented in black.
Since the vein authentication technology is not exposed to the risk of loss and has responsiveness to the risk of a hacking attempt, it has become a field in the spotlight recently.
Owing to high anti-forgery level, low false acceptance rate (FAR), low FRR (false rejection rate) and low FER (failure to enroll rate), the vein authentication technology applies to a high security field (e.g., national defense, public office, bank, etc.). And, application of the vein authentication technology to general fields is actively considered owing to accuracy higher than that of the fingerprint technology.
Vein authentication of the related art identifies or distinguishes a person through a non-contact sensing g of a finger vein.
Since the vein authentication technology of the related art uses an image sensor and an optical system, an image is taken by leaving a predetermined distance. And, the vein authentication technology has a limitation put on downsizing a sensor module due to restrictions put on an imaging device and a light source disposition.
Moreover, since the vein authentication of the related art depends on a non-contact sensing, it has difficulty in being installed on a mobile device or the like. Specifically, if the related art applies to a wearable device configured to come into contact with user's body, there is a problem that the user should space the wearable device apart from the user's body over a predetermined distance for the vein authentication.
In order to overcome the above problems and enhance user convenience by installation on a mobile device or the like, the demand for a device capable of detecting a vein image in the course of a contact between a user's body and a sensor is rising.